.header {
  height: 80px;
  background-color: skyblue;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 40px;
  color: #fff;
  position: relative;
} 

.header > span {
  color: red;
  font-size: 20px;
  position: absolute;
  height: 20px;
  right: 50px;
  top: 50%;
  margin-top: -10px;
}

.nav {
  height: 120px;
  border-bottom: 1px solid #ccc;
}

.banner {
  height: 600px;
  margin: 20px auto;
}

.banner .item {
  background-position: center;
  background-size: 1920px 580px;
}
